NEW YORK (AP) -- Police Commissioner Raymond Kelly on Thursday announced changes to officer training and supervision amid a growing public outcry and a federal lawsuit claiming the stop, question and frisk policy at the nation's largest department amounts to racial profiling.

Kelly sent a letter to City Council Speaker Christine Quinn detailing the changes. Quinn, a likely candidate for mayor, has been a vocal critic of the policy. Last year, more than 630,000 people were stopped, mostly black and Hispanic men. About half are frisked, and only about 10 percent are arrested.

Kelly said in the letter that the steps were meant to increase public confidence in the policy and that the department has reiterated its policy that prohibits racial profiling.

The department is also establishing an early warning system to identify officers who have received public complaints on the policy, and precinct commanders will be held accountable at weekly meetings.

Kelly also established a new course detailing how to conduct a lawful stop, following a review of training on the stop, question and frisk encounters. More than 1,500 officers who work in the highest-crime areas are receiving the training, and more will follow, Kelly said.

The news comes a day after a federal judge gave class-action status to a lawsuit by people who had been stopped. The lawsuit accused the police department of purposefully targeting black and Hispanic neighborhoods and said officers are pressured to meet quotas as part of the program and are punished if they don't.

U.S. District Judge Shira Scheindlin ruled that there was "overwhelming evidence" that the practice has led to thousands of illegal stops.

Kelly said in his letter to Quinn that the department has expanded community outreach and started a pilot program aimed at "vulnerable youth" that teaches them computer skills.

"It is our hope that this course will build lasting relationships and provide an outlined that might help foster positive interactions between these teenagers and police officers," Kelly wrote.

Mayor Michael Bloomberg defended the policy, which the police have said is a life-saving, crime-fighting tool and has helped lead the city to historic lows. Quinn has been a more vocal opponent.

She said the changes are a good start but more must be done.

"The NYPD, the Mayor, and the City Council have more work to do to ensure that all stop and frisks are appropriate. I know that we can both keep crime at these historic lows and protect the civil rights of all New Yorkers. That must be our commitment to the people of New York City," she wrote.

Some opponents of stop and frisk see Kelly's letter as an empty gesture.

"It's clear the police commissioner is feeling political pressure around the NYPD's abusive stop-and-frisk program, but this response is nothing more than a desperate public relations attempt," said NYCLU Executive Director Donna Lieberman in a statement. "The mayor and commissioner need to give up the spin and recognize that the NYPD's stop-and-frisk program is fundamentally broken. The NYPD is out of control, and the culture and practices of the Department need a full-scale overhaul so that the fundamental rights of all New Yorkers are respected and all communities can trust and respect the police."

Manhattan Borough President Scott Stringer, who hosted a panel on stop and frisk in Harlem Wednesday night, also said the reforms weren't substantial enough.

"Today's public relations gambit before the City Council by the NYPD does not honestly address a policing crisis which is dividing this city," he said in a statement. "The numbers speak for themselves: new data shows the City is on track to stop some 800,000 New Yorkers this year, the most ever. A reform plan that does nothing to reverse that trend is not real reform."